An individual may use a wide variety of different device platforms to create, receive and respond to emails, simple message system (SMS) and other electronic format messages, including computers (desktops, laptops, tablets) smart phones and accessories thereof (smart “watches,” wireless headsets and headphones, etc.). While this enables a user to engage in and maintain a conversation of related messages by using a variety of different devices, such freedoms may add complexities to tracking and searching for historic message activity. For example, use of subject terms may be inconsistent, or missing, across related messages that span different devices or application platforms, wherein a reply to an email having certain unique subject line data may be sent via a text message application that does not have subject line data fields, and therefore a subject line data search for all messages across different platforms or devices will not find the text message.